--- /dev/null
+
+include "logic/equality.ma".
+(* Inclusion of: LDA001-1.p *)
+(* -------------------------------------------------------------------------- *)
+(* File : LDA001-1 : TPTP v3.1.1. Released v1.0.0. *)
+(* Domain : LD-Algebras *)
+(* Problem : Verify 3*2*U = UUU, where U = 2*2 *)
+(* Version : [Jec93] (equality) axioms. *)
+(* English : *)
+(* Refs : [Jec93] Jech (1993), LD-Algebras *)
+(* Source : [Jec93] *)
+(* Names : Problem 1 [Jec93] *)
+(* Status : Unsatisfiable *)
+(* Rating : 0.00 v2.2.1, 0.22 v2.2.0, 0.29 v2.1.0, 0.25 v2.0.0 *)
+(* Syntax : Number of clauses : 5 ( 0 non-Horn; 5 unit; 4 RR) *)
+(* Number of atoms : 5 ( 5 equality) *)
+(* Maximal clause size : 1 ( 1 average) *)
+(* Number of predicates : 1 ( 0 propositional; 2-2 arity) *)
+(* Number of functors : 5 ( 4 constant; 0-2 arity) *)
+(* Number of variables : 3 ( 0 singleton) *)
+(* Maximal term depth : 3 ( 2 average) *)
+(* Comments : *)
+(* -------------------------------------------------------------------------- *)
+(* ----A1: x(yz)=xy(xz) *)
+(* ----3*2*U = U*U*U *)
+theorem prove_equation:
+ \forall Univ:Set.
+\forall f:\forall _:Univ.\forall _:Univ.Univ.
+\forall n1:Univ.
+\forall n2:Univ.
+\forall n3:Univ.
+\forall u:Univ.
+\forall H0:eq Univ u (f n2 n2).
+\forall H1:eq Univ n3 (f n2 n1).
+\forall H2:eq Univ n2 (f n1 n1).
+\forall H3:\forall X:Univ.\forall Y:Univ.\forall Z:Univ.eq Univ (f X (f Y Z)) (f (f X Y) (f X Z)).eq Univ (f (f n3 n2) u) (f (f u u) u)
+.
+intros.
+autobatch paramodulation timeout=100;
+try assumption.
+print proofterm.
+qed.
+(* -------------------------------------------------------------------------- *)